I think any network would accept an executable file, although you'll probably get some sh*t conversion when people are programmed to see a .pdf, .txt, etc. , see a .exe instead. I've seen it with 'locked' ebooks before, although that user paid for that file, and is more committed. Worth a shot, but don't expect a windfall, instead tie in a 'free' software inside the ebook givaway that is related (and give offers), and convert them there while you get a email for the ebook download.